The enormous explosion has levelled buildings, injured hundreds and killed an unknown number of people.

"It was horrifying" Commissioner Mullins told Sarah Macdonald on 702 Mornings of the moment that he first saw images of the disaster.

He was attending a meeting in Melbourne with every fire chief from Australia and New Zealand.

"The meeting just stopped. Everybody's jaws dropped," he said.

This isn't the first fertiliser explosion in Texas. 66 years to the day before the blast in West, a ship carrying ammonium nitrate fertiliser caught fire and exploded in the port of Texas City, killing over 500 people including all but one of the city's fire fighters.

"Every fire fighter in their recruit training hears about the Texas City blast," Commissioner Mullins said.

"It killed hundreds and just wiped out the fire fighters, they were all killed. It's something that every fire fighter is very well aware of," he added.

"Quite frankly, if you have a fire involving ammonium nitrate, you evacuate the area. You certainly don't put water on it, because that will probably cause it to explode," he added.

The Commissioner was also asked whether a similar disaster could happen in New South Wales.

"We certainly hope not. The stringent requirements that the Department of Planning, WorkCover and Fire and Rescue have on any company that deals with this product, we hope, would ensure that it would never happen here," he said.

"This product is very common. It's used as fertiliser; however fertiliser in Australia now has additives in it so that it's not as much of a blasting agent in years gone by."

You can listen to the whole interview with Commissioner Mullins by clicking on the player above.